Fig. 2

Histological findings of hyaline vascular Castleman’s disease (H-E staining). a The lymphoid follicles increased in number and had hypoplastic germinal centers (arrows). b The mantle zones were expanded with small lymphocytes with an “onion skin-like” aspect. c The follicles were usually penetrated by capillaries and showed a “lollipop” appearance. d Strong endothelial venule proliferation and hyalinization in the interfollicular zones was present